Pretty but dumb

Thank you for option to download videos but whats the point is I cannot erase them afterwards? I have to uninstall the app after a few days of usage just to get rid of all the old downloads.
The navigation is nice for the search of new courses, but it sucks if I already have a course in progress. Why aint there any fast access to "my" courses?
Hope you will fix these, right now the app is not usable.

Vega-m about Khan Academy, v3.1